blades



H. H. BLADES.

(No Model.)

OOMMUTATOR.

No. 437,844. Patented Oct. 7,-1890.

[NVENTUZZ o4. MYOLH'MO" WASNNGTOW u c UNITED STATES PATENT OFFICE.

HARRYII. BLADES, OF DETROIT, MICHIGAN, ASSIGNOR TO THE DETROIT MOTOR COMPANY, OF SAME PLACE.

COMMUTATOR.

SPECIFICATION forming part of Letters Patent No. 437,844, dated October '7, 1890.

Application filed November 12, 1888. Renewed August 13, 1890- Serial No. 361,854. (No model.)

To all whom it may concern:

Be it known that I, HARRY H. BLADES, a citizen of the United States, residing at Detroit, county of lVayne, State of Michigan, have invented a certain new and useful Improvement in Com mutators; and I declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it'appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to the manner of constructing and arranging the several parts of a commutator for electric dynamos and motors.

It is the object of my invention to construct a commutator that can be easily and cheaply made, the parts so shaped and arranged that as the periphery of the commutator is worn by the friction of the brushes the commutator still remains serviceable, and which shall possess other features of merithereinafter explained.

In the drawings, Figure l is a perspective view, and Fig. 2 is a longitudinal section, of the commutator. Fig. 3 is an end elevation, and Fig. 4 represents parts in detail.

The mode of constructing my commutator is as follows: A cylinder or thimble A, from which the segments a are formed, is first sawed radially for a distance from the end having the shoulder A into segments the desired width. The core 13 of insulation is then introduced. The outer surface of this core 15 conforms to the shape of the cylinder A and is adapted to receive the shaft. The ring: C of insulation is then introduced over the ends of the segments (I. and rests laterally against the shouldered ends A of the segments. Next, the ring D of insulation is introduced over the ends of the segments, and over this ringD and resting against the ring C is tightly fitted the metallic ring E. It will be seen that the shouldered ends of the segments are now held firmly in place by the ring E, which is thoroughly insulated from the said segments by the rings of insulating material C and D. The formation of the segments a may now be completed by sawing from the opposite end of the block, and the ring of insulation F introduced into a rabbeted recess on the ends. Sheets of mica G are now firmly packed between the segments a, except at the ends a, where the insulation is omitted to admit of the wires being attached to the segments.

It will now be seen that in a construction as above a commutator is obtained which is not only easily and cheaply made, but one that will not burn out the insulation between the segments, as has heretofore been the case when hard rubber, vitreous fiber, 850., have been used, such substances in charring being reduced (more or less) to the form of carbon, and so to a more or less perfect conductor.

The segments having been formed after the insulating-core has been inserted by sawing radially through the metallic cylinder, they are of necessity perfectly spaced.

The saw-kerfs may extend simply to the surface of the insulating-core, or one or more of them may be projected into the core itself. In the latter case the mica filling extending to the bottom of the kerf will serve to key the segments firmly to the core and so avoid the possibility of the core getting loose and turning within the segments.

That I claim is- 1. A commutator for electric machines, consisting of-a core of insulating material, se ments arranged parallel on the periphery thereof, a metallic ring fitted over the ends of said segments and insulated therefrom, a ring of insulating material over the opposite ends of said segments, and suitable insulating material between the segments, substantially as described.

2. A commutator for electric machines, consisting of a core of insulating material, segments arranged parallel on the periphery thereof, a metallic ring fitted over the ends of said segments and insulated therefrom, a ring of insulation over the opposite ends of said segments, and an insulation of mica between the segments, substantially as described.

3. A commutator for electric machines, the same consisting of a core of insulating material, segments arranged parallel on the peare keyed to the said core, substantially as riphery thereof, a metallic ring fitted overdescribed. 7 I the ends of said segments and insulated there- In testimony whereof I sign this specificafrom, a ring of insulating material over the tion in the presence of two witnesses.

5 opposite ends of said segments, and a filling HARRY H. BLADES.

of mica between the segments, one or more Witnesses: of said mica fillings projecting int-0 kerfs in V M. B. ODOGHERTY,

the surface of the core, whereby the segments SAMUEL E. THOMAS. 

